Fuse for projectiles



y 1935. N. E. METHLIN FUSE FOR PROJECTILES 3 Sheets-Shet 1 Filed Dec. 13, 1935 July 2, 1935. N, E, METHLIN FUSE FOR PROJECTILES Filed Dec. 15, 1933 3 Sheets-Sheet 2 Fig.2

y 1935. N. E. METHLIN FUSE FOR PROJECTILES Filed Dec. 13, 1933 5 Sheets-Sheet 3 Patented July 1935 ED; STAT PATENT orsice FUSE FOR PROJECTILES Nicolas Emilien Methlin, Paris, France, assignor to, Schneider & Cie., Paris, France, a limited joint-stock company of France Application December 13, 1933, Serial No. 702,255 In France April 28, 1933 r 10 Claims (01, 102-39) The present invention relates to a delayed arming percussion fuse, constructed in such a mannor as to operate by the drivingrin'of'one of the elements of the firing mechanism (thestriker for example) and by the inertia of the complementary element .(the percussion cap carrier), or viceversah,

The new fuse is characterized in-that it comprises, in combination with the front element of the mechanism (the striker) retained by a member withdrawable on impact, suchas a pin,.

a complementary movable'rear element, the percussion cap: carrier, ,forming' a plunger guided directly in the fuse body and carrying in its front part-a segment or other like safety member, which is guided withthe plunger over a portion of theqpath from the rear to the front through which the said plunger travels on operation, but

- which for arming, is rendered, radially withdrawable into a recess in the fuse body. The arming movement Ofqthfi safety member cannot occur, however, until the plunger has travelled over a suitable fraction 1ofits path, the safety member, during the time it is guided with the plunger formingan obstacle to the meeting the strikerand the percussioncap.

q a practical constructional form of the invention, the guide between. the plunger-like percussion cap carrier and the fuse body, is constructed with a suiiicientlysmall play, or through ,the medium of a fluid-tight joint, such that the plunger forms a piston and its forward movement is restrained by the impeded passage from the frontto the rear thereof of the air or, of an appropriate fluid or liquidcontained in the chamber closed by the front part of the fusebody.

'A practical constructional form of the invention is shownby way of example in the accompanying drawings in whichi they occupyat. rest; g V

.Figures2' and 3 are similar sections showing the membersin two successive operative positions.

Figure :4 is a similar part section showing the,

part playedby the safety member in the case of premature or accidental rupture of the striker retainingde'vice, 5

Figure. 5 is a'section along the line, 5--5 ,of Figure 3. s

,Figures 6 and 8-re1atelto a de1ay-action device combined with the fuse; Figures 6 and) '7 being vertical sections showing 'themembers-,in two,

diiferentx positions, and Figure 8 beinga pla sectionalong the line 8-8 ofFigure 6. ,4 I

-, Figure 1 is a section along the axisof the fuse,.

, the members being shown in the position which In these various figures, a denote'sa fuse body,

having an upper element a in which is guided conduit e in which may be placed adelay-action composition e According to the inventiom'the plunger 0, directly guided in the body 11, carries in its front portion a safety member 1, which'moves therewith and is guided in body a over a portion of the, path through which the percussion cap carrier c-d travels from the rear towards the front on operation. The guide for member 1 may bev constituted by an extension of the guide for the percussion cap carrier. The form of 'the example by a safety member 1 and the height to which its guide 7 extends are such that the said member, which is radially withdrawable by movementrelativ'e to the plunger under the action of the centrifugal force, possibly combined with the action: of. a H

spring, prevents, as long as it is guided from the rear to the front, any premature meeting of the striker b and the percussion cap d, even in the case of premature rupture of the pin 12 (as, indicated in Figure 4), or the premature operation of the percussion cap carrier by inertia. In the front portion a of the fuse b'odyis a chamber a of greater diameter than that of the guidefor the percussion cap carrier and safety member, thereby permitting the safety member I, when it has been advanced into saidchamber, to be withdrawn under the action of'the centrifugal 7 force, possibly assisted by the action of a spring I situated between the memberf and the percussion cap carrier. 7

The clearance between the'plunger c and the cylindrical guiding wall of the fuse body element a is made sufficiently small, or possibly a packing member such as a cup leather or a metal piston the head of ringis provided, so that the plunger will form a' piston and its forward movement will be re-' strained by the'passage towards the rear thereof of the air or any other appropriate fluid confined in the chamber 11 The forward'movement of "the plunger 'c for arming is normally ensured through the'medium of .a ring 9 guided within the lower recessed por tion of and adapted for longitudinal movement relative to the said plunger, andsubjected tothe action of a spring 9' bearing at its front end against a collar 9 of the ring, and at its rear end against the'block e. If a, delay-action block such as e is not combined with the fuse, the rear end of the said spring may bear on 'a shoulder of the body a, which shoulder would, at the same time, serve as support for the rear face of the.

flame from the percussion cap to the detcnator h;

In a groove g provided in the ringg, are locat '1 two elements forming springs g intended to engage a shoulder c of the plunger 0 and to hold the ring 9' in the position shown in Figures 2 am 3 after the projectile hasbeen fired.

At rest, the members occupy the position shown in Figure 1, any movement of rotation and any excessive movement of translation of the plunger being prevented by a spring bolt the tail of which engages a notch e on the head of thesaidplunger,

On the departure of the shot from the gun, the ring g lags behind by inertia, thereby compressing the spring g1, while the two springs 9 soon as they come opposite the rear large-bore portion 0 of the plunger below shoulder 0 can expand to take up a positionibehind the shoulder c as shown in Figure 2, and thereafter retain ring g .in a fixedfposition relative to the plunger 0. 1 On termination of the initial accel-- eration due to firing, the spring J1 expands and carries the ring g'forwardly and, through the medium of the springs 9 the percussion cap carrying plunger c-d. This forward movement is restrained or retarded by the obstruction to the flow of air or other fluid from the chamber a towards the rear of the fuse body offered by the relatively small clearance, or the packing joint provided, between the said plunger and the fuse body a. Premature rupture of the retaining member b during transport or while the projectile is passing through the bore of the gun, will not be able to bring about the operation of the firing mechanism, due to the fact that the member is situated on the path between the percussion cap and the striker, and prevents the point of the latter from contacting with the percussion cap until said member has reached its arming position' in chamber a. Forward movement of the plunger'c isrendered possible by the withdrawal of the bolt under the action of centrifugal force immediately after the projectilestarts to rotate, but the safety member 1 remains in the path of the striker b as long as the lower base'of the said member} has not clearedthe shoulder a defining the lower edge of' chamber a During the whole of this timeypremature inward movement of the striker, for example under the effect of encountering an obstacle in the vicinity of the muzzle of the gun, will not bring about the operation of the fuse, the striker, as'shown in Figure 4, being arrested inits inward movement a by the member under the actionof the centrifugal force combined with the action of the spring P. The members are then situated in the position shown in Figures 3 and 5. V

In the practical constructional form shown in the drawings, the path of radial outward movement allowed to the member f, is limited by flange 0 on the plunger head, which prevents the said member 7 from being jammed against the wall of chamber a? formed in forward portion a of the fuse body and forming a resistance to'the operation of the fuse by inertia. 'W hen the members are in this position-the fuse is armed and may operate by the driving of the striker into the percussion cap when the I projectile strikes an obstacle by its point. It may also operate by inertia when the projectile strikes an obstacle by its longitudinal surface, the percussion cap carrier then being driven forwardly with the withdrawn safety device'which it carries.

7 Thefuse which has just been described'may be combined, as moreover is the case for the constructional example shown, with a delayaction device soadapted that, in addition to the principal function which it fulfils, it combines the function, as shown previously hereinbefore, of serving as a support for the percussion cap carrier 0 and also as a member for centering and supporting oneend of the spring for the ring g for driving the said percussion cap carrier. 7

The delay-action device in itself may be given various constructional forms. In the example shown in the drawings, it comprises a bolt 7' v which is normally retained in the position which it has to occupy for direct operation (Figures'l,

6 and 8) by a pin k. In this position, theduct 7' provided in the bolt is opposite the axial'duct e of block e and permits the direct transmission of flame between the percussion cap'd and the detonator -h. If it is desired tocause the fuse to operate with delay after impact, it is merely necessary to drive out the pin is which enables the spring 7' to move the bolt :1 radially into a position in which it renders direct communication impossible between the duct e? and the'detonator h. In this case the flame from the per cussion cap 12' is transmitted to the detonator h by a conduit e in the block e and through the delay composition e What is' claimed is:

1. In a delayed arming percussion fuse mechanism fora projectilaa fuse body provided with an axial bore therein, the upper end of said bore being of a'larger diameter than the remainder thereof so as to form an enlarged recess insaid body, a striker carried by said fuse body with its lower end extending into said recess, means retaining said striker in inoperative position with impact, a percussion cap carrier of plunger-like construction mounted in and indirect sliding contact with the walls of said' axial bore, means for positively moving said carrierthrough said bore to arming position after the projectile has been fired, and a safety member mounted on the upper end of said carrier for'axial movement therewith but movable radially with respect thereto, said safety member also having'direct sliding contact with the walls of said bore and having a portion preventing contact between the striker and the percussion cap until said member is moved radially'outwardly into said recess at the upper end, of its axial movement. v

2. In a delayed arming percussion fuse mechanism for a projectile a fuse body provided'with an axial bore therein, the upper end of said bore being of .a larger diameter than the remainder thereof so as to form an enlarged recess in said body; a striker carried by said fuse body with its lower end'extending into-said recess, means retaining said striker in inoperative position until impact, a percussion cap carrier of plunger-like construction mounted. in and in direct sliding contact with the walls of said axial bore; a delayaction device-fixed in the lower portion of said axi'al' bore including a block upon which thej'lower end of said carrier rests when in normal unarmed position, means releasable only'after the projectile has been fired for normally. maintaining said carrier in said unarmed position, a springresting upon said block and adapted to positively move said carrier forward through said bore to armed position-after the projectile has been fired, and a safety member mounted on the upper end of said carrier for axial movement therewith but movable radially with respect thereto, said safety member also having direct sliding icontact 'with the walls of saidbore and having a portion preventing contact'between the striker and the percussion cap until said member is moved radially outwardly into said recess at the upper end of its axial movement. 1 v i i 7 1 3. Ina delayed arming percussion fuse mechk anismfor a projectile,'a fuse body provided with an axial bore therein, the upper end-of s'aidbore' being of a larger diameter than the remainder.

thereof so as to forman enlarged recess in said body, astr'iker carriedlby said fuse body fvith 'its lower end extending into said recess, means re taining said striker in inoperative position until impact, :a percussion cap carrier. of plunger-like construction mounted in and in direct sliding contact with the walls .of said axialbore, means for :positively. moving said carrier' forward throughlsaid .bore after the projectile has been fired, the clearance between said carrier and the. .walls .ofgsaid. bore being such that the forward movement of said carrier isretarded by a dash: pot action, and a safety member. mounted onthe upper end of said carrier for. axial movement body, a striker carried by said fuse body with its lower end extending into said recess, means re-.

taining said striker in inoperative position until impact, a percussion cap carrier of plunger-like construction mounted in and in direct sliding contact with the walls of. saidaxial bore, a safety member mounted on the upper end of said'carrier for axial movement therewith but movable radially with respect thereto, said safety memher also having direct sliding contact with the walls of said bore and having a portion preventing contact between the striker and the percussion cap until said member is moved radially outwardly into said recess at the upper end. of its axial movement, and means for positively limiting the extent of the radial movement of said safety member in said recess so as to prevent contact thereof with the walls ofsaid recess.

5. In a delayed arming percussion fuse .mech-.

an axial bore therein, the'upper'end of'said bore anisni for a projectile, afuse body provided with being of a larger diameter than the remainder 7 thereof so as to form, an enlarged recess in said body, a; striker carried'by saidfuse body with its.-

lower end extending'into said recess, means retaining saidlstriker ininoperative position until impact, a permission cap carrier of'plunger-like construction. mounted in and in direct sliding contact withthe Walls of said axial bore, means for positively moving said carrier forward through said hereafter the projectile has been, fired,.a safety member mountedon the upper end of said carrier for axial movement therewith but movable radially withxrespect thereto, a spring interposed, between said carrier and safety mem-;

ber and tending to move the latter radially? outwardly with respect. to the-former; said safety member, also having direct. sliding contact with the walls of saidbore. and having a portion preventingicontacti.between .the striker and the:

percussion cap until said member is .moved radie ally outwardly into said recess at the upper end of --its axial. movement, andmeans mounted on said carrier; for positivel'y'limiting the extent of the radial movement of said safety member in said recess so as to prevent contact thereof with the walls of said recess. 5

6.. In a delayedarming percussion fuse mechanism for a projectile, a fuse body provided with an, axial bore thereinfa percussion cap'carrier of plunger-likeconstruction mounted inland in direct sliding contact with the walls of said bore,;

said carrier having an axial recess formed therein, means releasable only after the projectile has been fired for normally maintaining said carrier in a' rearward'unarmed position, and means formoving'said carrier forward to armed position after firing comprising an inertia ring mounted within said carrier recess for axial movement relative thereto, a spring interposed between said ring and a fixed portion of thefuse body and exerting a forward thrust against said ring, said spring. normally maintaining said; ring in a position adjacentthe forward end of said carrier recess but yielding to the inertia 'of said ring when the projectile is fired to permitsaid ring to'move rearward-relative to said carrier,

and means for locking said ring to said carrier' when the ring reaches its rearward position under the influence of the forces exerted at the .time of firing, whereupon said spring moves both said ring and carrier forward to armed position. '7. In a delayed arming percussion fuse mechanism for a projectile, a fuse body provided with an axial bore therein, a percussion cap carrier of plunger-like construction mounted in and in direct sliding contact with the walls of said bore, said carrier having an axial recess formed therein, a delay-action device fixed in said axial bore behind said carrier including a block upon which the rear end of said carrier rests when in normal unarmed position, means releasable only after the projectile has been firedfor normally maintaining said carrier in said unarmed position, "a tubular extension projecting forwardly from said block into said carrier recess, said extension and block having anaxial flame transmitting conduit therethrough, and means for moving said carrier forward to armed position after firing comprising an inertia ring mounted within said carrier recess for axial movementrelative thereto and guided upon said tubular extension, a spring interposed betweensaid ring and said delay-action device block and exerting aforward thrust against said ring, said spring normally maintaining said ring'in a position adjacent the forward end of said carrier recess, but yielding to the inertia of said ring when the projectile is fired to permit said ringlto move rearward relative to said carrier, means associated with said tubular,

extension for determining said forward position of the inertia ring, and means for locking said ring to saidcarrier when the-ring reaches its rearward position under. the influence of the forces I exerted at the time of firing, whereupon said spring moves both said ringsandcarrier forward to armed position.

8. In a delayed arming percussion fuse mecha' nism for a projectile, a fuse body provided with an axial bore therein, the forward end of said bore being 1 of a larger diameter than the rej-l mainder thereof so as toform an enlarged recess, a striker carried by said fuse body with its lower end extending into said recess,-a percussion cap carrier mounted in said hole for forward axial movement therein to armed position, means releasable onlyafter the projectile has been fired for normally maintaining said carrier in unarmed position, means for moving said carrier forward to armed position after firing comprising an inertia ring moiuited for axial movement relative to said carrier, a spring interposed between said ring and a fixed portion of the fuse body and exerting a forward thrust against said ring, said spring normally maintaining said ring in a posimember mounted on the forward end of said car-- rier foraxial movement therewith but movable radially with respect thereto, said safety member having a portion preventing contact between said striker andthe percussioncap until the forward end of said carrier reaches the forward portion of said bore and said safety member is moved radially outwardly into said recess.

9. In a fuse mech'anism forprojectiles whereinv tile from the gun, thereby compressing, the spring,

means for locking said inertia member to said carrier in its rearward position, and means independent of said'inertia member for normally locking said carrier to said fuse body in unarmed position, said last-named locking meansbeing automatically releasable after they projectile is in flight so as to permit the force of the compressed spring to be transmitted to said carrier and to move, the latter the striker. a

10. In a fuse mechanism for projectiles wherein a percussioncap is moved axially forwardly with respect to the fuse body into position for firing contact with a striker, the combination'of a carrier for said percussion cap slidably mount ed within said fuse body, an inertia member mounted for axial movement relatively to said carrier, a spring interposed between said inertia member and a portion of the fuse body, said inertia member normally occupying a'position forward with respect to said carrier but movable rearwardly with respect thereto upon firing of the projectile from'the gun, thereby compressing the spring, means for locking said inertia memher to said carrier in its rearward position, and a locking bolt mounted in said fuse body and. extending radially inwardly thereof to engage said carrier when the latter is in its at rest'pos'ition, said locking bolt being automatically withdrawn under the action of centrifugal force after the projectile is in flight so as to permit the force of the compressed spring to be transmitted to'said carrier and to move the latter axially forwardly toward the striker.

NICOLAS EMILIEN METI-ILIN.

axially forwardly toward ill 

